|Bauermann, Fernando - Universidade Federal De Santa Maria|
|Falkenberg, Shollie - Elanco Animal Health, Inc|
|Wolff, P - Nevada Department Of Wildlife|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/5/2016
Publication Date: N/A
Technical Abstract: Objective: In addition to the recognized/classic species within the pestivirus genus there are putative species. One of these is pronghorn virus (PHV). PHV was first isolated from an immature, blind pronghorn antelope in the state of Wyoming. The objectives of these studies were to determine level of genetic and antigenic cross reactivity between PHV and other pestivirus species, examine the incidence of exposure to the emerging pestivirus, pronghorn virus (PHV), in wild ungulate populations, and observe clinical presentation in domestic goats and white tail deer following exposure to PHV. Materials and Methods: Sequencing of the genomic RNA of pronghorn virus from the cell culture supernatant was done using the Ion Torrent and Illumina MiSeq sequencing protocols, as previously described. The 3' end of the genomic RNA was confirmed by 3' RACE using a primer set designed to amplify the 3' terminal 600 bases. Hyperimmune sera against bovine viral diarrhea virus 1 (BVDV1), BVDV2, border disease virus (BDV) or PHV were produced in goats and cross neutralization studies performed. Serum and whole blood was collected from mule deer, big horn sheep, mountain goat and pronghorn antelope residing in the US state of Nevada. Some tissue samples were collected from wild ungulates found dead in the field. Virus neutralizations were conducted with these sera using BVDV1, BVDV2, BDV and PHV strains. PCR, using pestivirus specific primers, was done on serum, tissue and whole blood samples. The resulting amplicons were sequenced and phylogenetic analysis performed to determine pestivirus species. Domestic goats and white tail deer fawn were exposed to PHV by oral/nasal inoculation and observed for clinical presentation. Results: Phylogenetic analysis showed that PHV is more distant from the recognized species of pestivirus than the recognized species are to each other. Antigenic comparison, using hyperimmune goat serum, demonstrated that the antigenic cross reactivity between PHV and the recognized pestivirus species is low. PHV was detected in mule deer, big horn sheep and mountain goat samples. Serological surveys of pronghorn antelope populations revealed higher titers against PHV than BVDV1 or BVDV2. Clinical presentation following infection of domestic goats with PHV included mild, short-term pyrexia and a decrease in circulating lymphocytes. Infection of white tailed deer resulted in death in 2 out of 6 animals inoculated. Pre-existing antibodies, against BVDV in deer, did not prevent replication of PHV or decreases in circulating lymphocytes. PHV was not transmitted to pen mates following infection of either goats or white tailed deer. Conclusions: Despite evidence that pestiviruses circulate in wildlife populations, the impact of exposure and prevalence of these infections are largely unknown. The antigenic and genomic differences between classic pestiviruses and the emerging pestivirus PHV suggest that diagnostics designed to detect classic pestiviruses may fail to detect PHV. PHV appears to be replicating in multiple free ranging ungulate populations in the US and may contribute to immunosuppression and death loss in these populations. Further studies need to be done to determine if PHV can be transmitted from wild ungulates to domestic animals.